This Wrox Blox explains a custom design for integrating Microsoft CRM 4.0 with external applications. The author helps readers understand Microsoft CRM's integration capabilities and design approach for integrating Microsoft CRM with other applications and implementing it by integrating Microsoft CRM with WSS Microsoft Office SharePoint Server (WSS). The Wrox Blox begins with an explanation of the requirements for a generic design pattern and discusses different components of Microsoft CRM 4.0 that aid in integration. As an example, the complete source code and step-by-step guide to integrate Windows SharePoint Services with Microsoft CRM 4.0, are included. The integration solution involves MSMQ and Windows Services to provide reliability and extensibility to the solution. After reading this Wrox Blox, readers should be able to easily design an integration solution for integrating Microsoft CRM 4.0 with any external application.